He's a comic foil for superheroes Mr. Scarlet and Pinky. An opera wannabe, he's literally booted out of the "Municiple [sic] Opera House" into the rain and catches a cold. He stumbles on a radio amateur show, and is forced to sing with a stuffy nose- but it improves his voice and he becomes a sensation. But then he has to keep his cold to keep his fame. So Mr. Scarlet and Pinky drag him out in the rain, and push in him whatever water is nearby.
Meanwhile, other singer Vermin Base is jealous cause he's losing jobs and sponsors to Largo, and hires goons to kidnap him. Then Mr. Scarlet gets the dumb idea to let Largo get kidnapped, since the rough treatment is sure to make the cold worse. But then Largo spills his secret to the kidnappers, and they try to get him healthy, and Mr. Scarlet has to rescue Largo, AND treat him bad enough to stay sick.
While the superheroes are busy beating up mobsters, Largo ends up in the hospital where they give him a tonsillectomy. But instead of ruining his voice, "that tonsil operation has turned my voice into the operatic tenor of the world! Now I have a 99 year contract with the opera company!"